Question

Solve the following quadratic equation by formula method

3y² – 20y – 23 = 0

Answer 1

a = 3, b = – 20, c = – 23

x = `(-"b" ± sqrt("b"^2 - 4"ac"))/(2"a")`

= `(20 ± sqrt(400 - 4(3) (- 23)))/(6)`

= `(20 ± sqrt(400 + 276))/(6)`

= `(20 ± sqrt(676))/(6)`

= `(20 ± 26)/(6)`

= `(2(10 ± 13))/(6)`

= `((10 ± 13))/(3)`

= `(10 + 13)/(3)` or `(10 - 13)/(3)`

= `(23)/(3)` or `(-3)/(3) = (23)/(3)` or – 1

The solution set is – 1 and `(23)/(5)`